Autism has proven to be one of the most difficult-to-treat indications, but troublesome symptoms may someday find new relief. Last week, Roche Holdings (NASDAQOTH:RHHBY) announced it had received breakthrough therapy status from the Food and Drug Administration for balovaptan, a potential therapy for autism spectrum disorder.

If future trials confirm balovaptan's promise, it could improve social interaction and communication in people with autism.

First, some background

People with autism spectrum disorder experience a wide range of symptoms, including difficulty interacting and communicating with others, repetitive behavior, and limited interests. Those with ASD can also experience other symptoms, including anxiety, seizures, language challenges, sensory issues, attention deficit, mood changes, and anger.

Researcher work together at a table in a laboratory.

IMAGE SOURCE: GETTY IMAGES.

Autism is four times more likely to be diagnosed in boys than girls, and the U.S. patient population is estimated to be above 3 million people. It's estimated that there are over 24 million people with autism worldwide. Currently, there is no cure.

The drug that may help someday

In midstage studies, Roche's balovaptan has shown promise that it may help improve social behavior in autistic adults.

Balovaptan is a V1a vasopressin receptor antagonist that blocks or dampens the biological response to vasopressin, a hormone. Historically, vasopressin is known for its role in regulating the volume of water in the body and influencing blood pressure. However, researchers increasingly believe that vasopressin imbalances may contribute to autism, particularly in boys, in whom high levels of vasopressin have been connected to anxiety and aggression.

At the International Meeting for Autism Research in San Francisco last year, trial data was presented showing that balovaptan taken once daily for 12 weeks significantly improved socialization and communication abilities, as measured by the Vineland Adaptive Behavior Scales. Specifically, study participants who took intermediate and high doses of balovaptan saw their scores on this scale improve by roughly four to five points, results that researchers said were "above the threshold for what we consider a minimum clinically important difference."

What's next

The FDA designation of breakthrough status can accelerate balovaptan's development, but there's still a lot of work to be done.

Before the FDA will consider approving balovaptan, Roche needs to complete its ongoing study in children between the ages of 5 to 17 years. If results from that study are also positive, then Roche can sit down with regulators to discuss whether any additional trials will be necessary before filing for approval. According to ClinicalTrials.gov, we have some waiting to do; the estimated completion date for the children's study isn't until April 2019. Based on that timeline, we're still a couple of years away from knowing that balovaptan is a safe and effective treatment for symptoms associated with autism. 

Todd Campbell has no position in any of the stocks mentioned. His clients may have positions in the companies mentioned. The Motley Fool has no position in any of the stocks mentioned. The Motley Fool has a disclosure policy.